Double-pendulum spray gives this graffiti bot some style

Here’s an art exhibit that does its own painting. The Senseless Drawing Bot (translated) uses the back and forth motion of the wheeled based to get a double-pendulum arm swinging. At the end of the out-of-control appendage, a can of spray paint is let loose. We’re kind of surprised by the results as they don’t look like a machine made them.

The video after the break gives a pretty good synopsis of how the robot performs its duties. The site linked above is a bit difficult to navigate, but if you start digging you’ll find a lot of build information. For instance, it looks like this was prototyped with a small RC car along with sticks of wood as the pendulums.

I thought double pendulums exhibit chaotic behaviour. Sure with identical start characteristics it would be initially repeatable, but presumably bearing wear in the linkages would cause differences to occur over time, but that would still require everything else to be the same – which it highly unlikely down to even the mm level

Optical character recognition is good enough that I would consiter having the robot train itself to make shapes that it recognises as the desired letters. It would hopefully accept varied enough writing to to still appear freeform while being legible. While allowing the robot to change arm length might help make the top and botton constraints less obvious, among other possible improvements, I think it’ll also be less apparent if the density of lines is reduced, since individual arcs often don’t reach those limits.

In the main image used in this article, the right side of the squiggles seems to spell “Rao”, or perhapes “Ralo”.

Could be used by companies, municipalities to “dis” existing graffiti for a lower cost than having to repaint (and produce a fresh canvas for the taggers). Subway operators and railroads could place a stationary one along side their tracks and “redux” each car as it rolls past.